


Unwritten

by Mangerine



Category: World Trigger (Anime & Manga)
Genre: M/M, Pining and Teenage Angst, Soulmate AU, Tachikawa and Yuma have a lot in common if you think too hard about it
Language: English
Status: Completed
Published: 2020-01-02
Updated: 2020-01-02
Packaged: 2021-02-27 15:15:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,039
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22089229
Author URL: https://archiveofourown.org/users/Mangerine/pseuds/Mangerine
Summary: Soulmates were people who understood you, simply put. People who were, at their core of their being, compatible with you. What you love, what you hate, what makes you cry yourself to bed at night and what makes you brave enough to wake up the next morning, the soulmate understands, and the soulmate accepts - Only, Osamu's soulmate just called to say he never wants to meet him, and hangs up. That was ten-and-a-half years ago.orEveryone's got someone, except Mikumo Osamu
Relationships: Kuga Yuuma/Mikumo Osamu
Comments: 13
Kudos: 115





	Unwritten

_What’s your name?_

Mi-ku-mo O-sa-mu, he writes back, slowly. How fortunate that his soulmate wrote to him a week after he learnt how to write his whole name! Osamu thinks, with a washable green marker in his hand.

_I see._ Comes the short reply, before it’s wiped away entirely.

 _How old are you?_ Is the next question that comes, Osamu presses the marker to his right arm and squiggles, _Four_ , before pausing for a moment and adding on _and a half_.

_I see._ Comes the reply again. Then it’s wiped off.

Osamu asks what his soulmate’s name is, but the answer doesn’t come.

Half a month later, the call comes.

“Mikumo residence, who is this?” his mother answers a few paces away from where he sits, finishing his lunch.

“I…I see.” She says, hesitant “How did you get this number?”. Her brow furrows at the stranger’s reply. “I don’t suppose you’ll want to reconsider this over dinner?” then “I see,” she replies, rather coldly. Osamu wonders if adults carry entire conversation that way, repeating _I see_ in various intonations.

“Talk to him?” His mother exclaims, looking as though she’d stepped in something disgusting. She flicks her eyes over to Osamu, schooling her expression into something more neutral, though barely masked anger shines in her eyes.

“Fine.” She says, “But you’ll be on loudspeaker. I won’t hesitate to end the call if- yes, as long as we’re clear.”

She pulls him from his half-finished omelette rice and sits him on the sofa, staring in his eyes for a good few moments. Osamu hears gears clicking behind her eyes; sentences forming and breaking and forming again before she finally takes a deep breath.

“Osamu dear, you remember what I told you about soulmates?”

Osamu nods.

Soulmates were people who understood you, simply put. People who were, at their core of their being, compatible with you. What you love, what you hate, what makes you cry yourself to bed at night and what makes you brave enough to wake up the next morning, the soulmate understands, and the soulmate accepts.

“My soulmate knows me best,” Osamu says, “like why I like croquettes, and the colour green.”

Osamu thinks he sees tears form in his mother’s eyes.

“Yes, honey, but well, sometimes, it doesn’t always- sometimes, just because they understand, doesn’t mean they – people lead different lives and – it’s not as simple as –” Kasumi falters, and then she sighs.

“Osamu, honey.” She says, “You’ll understand when you’re older. I promise. But for now you’ll need to be brave, alright?”

Osamu nods simply because he thinks it’s the right thing to do. His mother presses a button on the phone and holds it in front of him.

“Go ahead,” she says.

For a moment, nothing but static crackles from the other end, but then a low voice comes through.

“Mikumo kun?”

“Yes?” Osamu replies, nervous suddenly. His mother places a comforting hand on his knee.

“This is your soulmate speaking,” the voice says. Static pops on the other end like knuckles being cracked. “I have something important to say, but it’s not going to be very nice, do you still want to hear it?”

“…Yes please,” Osamu replies,

“Alright,” The voice says, “Mikumo-kun, you’re four this year, yes?”

“Uh huh,” Osamu says, “And-a-half,”

“And-a-half,” his soulmate amends agreeably. “Well, Mikumo-kun, I’m thirty-one,” he says, “and one-sixths, I suppose.”

“The thing is, Mikumo-kun, for reasons beyond our age, we lead very different lives, or-” a pause, “or rather, I hope we will.”

“It’s nothing personal, I simply think it is safer if we do not meet.”

“I see,” Osamu mumbles, realizing then that that was simply what adults say when they don’t know what else there is to be said.

“I knew you’d understand,” the voice says.

Osamu does not.

“Goodbye, Mikumo-kun”

With that, his soulmate hangs up on him.

x

“What a dick,” Rinji says when he first hears the story, idly bouncing a tennis ball against the ground.

“I heard that!” Chika says behind them, two plastic water bottles in hand. “Put 100¥ in the cuss jar when we get home!”

“Got it,” Rinji says, taking a swig from the purple bottle in Chika’s hand.

“That’s _my_ bottle!” she whines, but Osamu knows by now she doesn’t truly mind.

“Right, right,” he laughs, pulling off his sun visor and plopping it on her head. “You drink too, don’t get dehydrated.”

“Thanks Chika,” Osamu says as he takes his green bottle from her, “I was just telling your brother how my soulmate cut things off over the phone”

“And that’s supposed to be the guy that understands you best? You’re not going to become some jerk that dumps their partner over text are you?” Rinji teases.

Osamu blusters, “Of course not! Now that I know how much it hurts --!”

“There it is,” Rinji says, fixing his gaze back on the other end of the tennis court. “told you I could get him to admit it,”

Chika pointedly avoids eye contact.

“What- What’s going on?” Osamu asks, suddenly lost.

“You look sad every time someone talks about soulmates, and Chika got worried,” Rinji says, busying himself with lobbing a ball over the net rather than looking at Osamu.

“Sorry,” Chika says, “but I promised I wouldn’t tell him, and I didn’t! You told him yourself!” before she deflates a little, and repeats, “sorry”.

“Sneaky!” Osamu scolds, both siblings not looking at him – Chika scuffing her shoes on the rough tarmac and Rinji smugly swinging a ball to the other court with a resounding _thwak_! – “No wonder you two are soulmates!”

“Ha,” Rinji says in reply, completely unapologetic, “well, don’t worry too much, Osamu, this soulmate thing is overrated anyway,” he says, finally looking at Osamu again.

“Easy for me to say, I know, but really, just because the guy that you’re most compatible with was a flake doesn’t mean the guy you’re,” he makes a indecisive hand gesture, “second-most compatible with? Is gonna turn out the same, keep your head up.”

_Not helping_ , appears on his left wrist, hidden from Osamu. Rinji glances at where Chika was standing under a nearby tree with a marker in her hand, judgement of his incompetency clear in her eyes.

Rinji sighs, wondering why his sister thought he’d be good at comforting when she wasn’t. Of all people, he’d expect her to understand how bad he was at this. “Come on, let’s see if I can teach you how to get the ball over to the other court at least” he says.

If you’ve got a tough egg you can’t crack, he thinks, just distract.

Two minutes later, Osamu smashes his racket into Rinji’s ass, and the latter ends up donating his weekly allowance to the cuss jar.

x

 _‘You’re not going to become some jerk that dumps their partner over text are you?’_ _he says,_ Osamu thinks bitterly two years later. Beside him, Chika sobs quietly, arms full of messages with no reply. In his hand is his cellphone with Rinji’s message:

_“Osamu, if you’re reading this automated message, it means that I’m not coming back….”_

x

The significance of soulmates waxes and wanes daily in the double lives he leads. At Border, the only compatibilities that mattered were those on the battlefield, the understanding and trust between him and his team. With the way he was trying to understand his opponent’s strategies and thinking, he might as well consider the entirety of Border his soulmates. It was a profession of neutrality and objectivity – you wouldn’t last a day if you took it personally each time a friend stabbed you without blinking in rank wars.

When he triggers off it’s another battlefield altogether. A day barely passes where a teacher doesn’t chastise a student for doodling on their hands instead of paying attention in class. Comics of schoolgirls finding out their soulmates were the hottest stud in school were frequently traded in class, and collectively swooned over.

He’s not bitter, he’s _nauseated_.

“Woah, you’re doing really well in English these days!” He hears a girl exclaim as he heads to the roof with Yuma.

“Well, you know,” her friend giggles, with a poorly concealed and well-stroked ego, “I have to talk to my soulmate somehow!”

Osamu rolls his eyes instinctively, and if Yuma notices, he doesn’t say anything.

¦

Autumn is blessedly cool after months of exhausting summer, and the tiles on the rooftop are don’t scald them when they sit anymore. The lush green view they usually enjoy is now blooming red with dying leaves. Osamu tugs the lid off his lunchbox – and promptly pulls it away – seconds before Yuma’s chopsticks come into dangerous proximity of his croquettes.

“Nice try,” Osamu says, scooting away from a drooling neighbour, “You have your own lunch, you bottomless pit”

“I never see you move that fast in rank battles,” Yuma comments flatly. It’d hurt, coming from anyone else, that is. Yuma is blunt and honest at his core, so Osamu doesn’t take it personally, and simply makes a show of eating his lunch. Yuma face scrunches up.

“Just half--!” Yuma tries again, pouncing when he thinks Osamu’s guard is down. No such luck. The croquette eludes him.

Osamu laughs when Yuma relegates himself to his sandwich lunch for the third day in a row. He’d been complaining about how planning his diet has become doubly hard with Replica gone, what with the trouble of grocery shopping and how he couldn’t reach the spice shelf at home. When Yuma reaches for the second half of his sandwich, Osamu slides a croquette over into his lunchbox, and drops in some of his omelette as well.

“Trade you,” he says softly, and Yuma smiles at him brightly.

The sandwich is awful, but Osamu savours it slowly still. The weather is nice, he thinks and the lessons they have for the rest of the day are easy. It was shaping up to be a nice day, he thinks. Best of all, the company today was….

He knows what this is, and he suspects Chika does too, with the way she pulls Izuho to the canteen instead of joining Yuma and himself on the roof. This is nice, he thinks again. Even if the waters between him and Yuma are deep and uncertain, they’re calm for now.

_After all_ , Osamu thinks, _neither of us write to our soulmates_.

x

He discovered that fact when the sky was dark enough that Yuma couldn’t see how red his face was.

“Do you have a soulmate?”

“I did,” Yuma says, “but I can’t see what they write to me, not in this body anyway. I feel it sometimes though, like an itch, but nothing shows up”.

Yuma didn’t look upset, so Osamu doesn’t feel guilty when he nearly smiles, silently grateful that both their arms were unwritten. He’s never gotten to pine for a romantic soulmate, spending his time watching small messages from his father pop up on his mother’s arm instead, vacantly wondering.

“Your mum’s cooking is great as usual,” Yuma says, snapping him from his reverie, pressing the lid back onto his empty lunchbox.

Osamu cooked lunch himself that day, and he’s nearly tempted to say as much, until he remembers the girl from before, giggly and effervescent from talking about her soulmate.

“If you’re really having trouble with cooking, I’ll help you out after school,” Osamu says instead.

“That’ll be a great help,” Yuma says, “I had to ask three strangers to explain what a cauliflower was the other day, it was awful.”

Osamu laughs, it was a good day.

And it was, up until they were leaving school.

“Kuga-kun” Yuma reads, from the faintly perfumed card he finds in his shoe locker, “I believe I am your soulmate. Will you meet me after school today in the art room?”

He flips the card over, but it only has a generic floral print, with no indication of the sender’s identity.

“Huh,” Yuma says, re-reading the card.

Osamu feels stupid, stupid, **stupid** , with recipes he’d researched all night bookmarked in his phone and coupons he clipped from the newspaper in his wallet. _Of course_ , he thinks, _he said he couldn’t read what his soulmate wrote, but if he wrote something and his soulmate saw…_

All at once, the tight pain in his chest gives way like a trapdoor, and Osamu smiles through the familiar emptiness.

“I see, can’t be helped then,” he says, and he hears the click of a phone in his mind.

He directs Yuma down the halls (“Really, you should know your way there by now”), and resists the urge to make him walk the long way out of spite. He walks the long way to Tamakoma himself, unwilling to walk past the greengrocers.

x

“Hyuuuuse” Yotaro whines, “Pleeeeeeeaaaaseeeeeeee”

“No,” Hyuse snaps, before willing himself to take a deep breath, “You’ll spoil your dinner,”

“I’ll let you pet Raijinmaru’s belly!” Yotaro tries, and when Hyuse remains unmoved, wails, “Is this how you treat your soulmate?”

Hyuse sighs, and Raijinmaru snorts when he pets her particularly roughly, “No more dorayakis” he says again.

Yotaro uncaps a purple pen and draws a thick handlebar moustache over his upper lip.

“I don’t negotiate with bullies,” Hyuse says, somehow maintaining an air of dignity and poise with grapey facial hair.

Yotaro flops at his feet, and Hyuse peels him from the floor to wipe off both their moustaches.

For the umpteenth time, Osamu wonders if this really was the stronghold of Border’s finest warriors.

“Osamu-“

“No” Osamu says, pulling the coupons out his wallet, and after a second of contemplation, ripping them up, wadding them in a ball and slamming them into the trash.

“Hyuse, do you have time to spar?”

“Am I so bored that I’d spend time virtually killing you for amusement?”

Osamu stuffs his wallet back in his pocket and pulls out his trigger.

“….Yes. Yes I am. Use training room two, Raijinmaru had an incident in room one” Hyuse says, standing up with a faintly pink mark below his nose.

_Don’t flinch_ , he repeats like a mantra. His trion body’s pain setting is set at maximum, and Hyuse comes at him without holding back, a silent acknowledgment of him as an equal. _Don’t flinch don’t flinch don’t flinch,_ he thinks, screaming out Asteroid! And Thruster on! instead of This isn’t fair! and why? why? why?

It becomes a habit, the way he dips himself in his work. Effort wouldn’t betray him here, and he’d rather drown in his responsibilities than parch himself, thirsting for what he cannot have. It’s happening, and he can’t stop it, the way he feels around Yuma, or worse, the way he feels after nightmares of a world without him. It’s not weakness, he knows, but it feels like leaving the door open as you sleep, like crossing a road with your eyes closed, an anxiety that he can’t tame.

“We’re done,” Hyuse says, deactivating his trigger.

“One more round,” Osamu says, trion leaking out from his chest.

“We’re done,” Hyuse repeats, “It’s dinner time, I expect you’re helping me cook after wasting my time. Your heart wasn’t in it at all.” He spits out, then leaves.

_Don’t take it personally, Hyuse_ , he wants to say, but freezes where he lies.

_It’s not personal, after all_.

That’s what his soulmate said, wasn’t it? It isn’t personal, I just hurt you because I believe I know better, because it’s more convenient for both of us if we don’t meet.

 _You dick_ , Osamu thinks viciously, loosening his grip on the reins of his anger. _I don’t even know you, but I understand you. I don’t want to understand, not in the least, but I do._

The vacuous numbness suddenly mutates into something painful.

_I don’t want to become like you_ , Osamu thinks, making his way to the kitchen, _but who are you?_

x

Jin walks in just as Osamu turns the stove off. He takes one look at Osamu and walks back out the door.

“Jin-san!” Osamu yells, running after Jin, right out the door, apron still securely fastened around him.

“No!” Jin yells, sounding like a filthy child running from their bath.

“Please!” Osamu yells, “You know who he is, don’t you? My soulmate?”

Jin whines as Osamu catches the edge of his jacket and tugs hard.

“Could you imagine life without knowing Tachikawa-san?” Osamu says.

“Trying to guilt me won’t work.” Jin replies blandly, but buckles anyway.

“This is gonna be so awkward”, he grumbles.

x

It’s late evening as he gathers his documents and walks out the office. The halls are quiet tonight, with agents at home, happily playing civilian.

 _No rest for the wicked,_ he sighs, and exits the elevator to the carpark. It’s mostly empty, save for his own car – and his soulmate standing right beside it.

He grips his suitcase tighter.

“Agent-” he starts, then halts, “Mikumo-kun” he corrects. No point hiding behind formalities, he supposes.

“Commander Kido,” Osamu greets.

No rest at all, Kido straightens and gestures to his car, “Let’s talk inside, it’s getting cold.”

x

Yuma helps himself to dinner without washing his hands.

“Where’s Osamu?” he asks past a mouthful of curry. Konami didn’t cook it this time; the vegetables were all cubed neatly, almost minced. A strange choice, the cook must have had some anger to work off on the chopping board – probably Hyuse.

“Out shattering our social reality as we know it,” Jin mutters into his spoon,

“Oh, ok,” Yuma replies, impassively. “I met my soulmate today,”

Konami chokes on her rice.

“That’s nice,” Jin says, uncharacteristically distracted, as if he were actually second-guessing if he’d made the right choice.

“What- what did- How- What did they say?” Konami asks.

“Can’t tell you everything, but she’s a civilian, found out we were soulmates when I wrote my grocery list on my hand and it showed up on her”

“And?” Konami presses.

“And nothing. She’s gay, and lonely I suppose, she just wanted someone who’d understand.”

“What about you?”

“I’m gay too,”

“No, Yuma, I meant-“

“Oh, Kuga,” Osamu says, letting the cold autumn air in as he pulls open the door. “Can you meet me on the roof when you’re done?”

“Roger,” he says as he wolfs down his dinner.

“Yuma, wait-” Konami starts, but stops when Jin places a hand on her shoulder.

Yuma brings him a warm cup of tea.

“Sorry about this afternoon,” Yuma says,

“How’d it go?” Osamu replies instead of saying it’s ok. No point lying to Yuma, after all. 

“She has someone she likes, and she was feeling pretty antsy, I guess.”

“Oh? Must have been pretty desperate if she could only trust her soulmate about it,”

“Somewhat,” Yuma agrees.

Osamu presses his lips to the warmth of the cup.

“I met my soulmate too,” he says,

Yuma falters for a second, “How?”

“How?” Kido asks, and the heater does nothing to remove the chill between them.

“I have my sourc-“

“Jin” Kido punctuates, tensing for a moment, before shrugging.

“And? What did you hope to achieve from meeting me tonight?”

“Why did you let me join Border?”

“If I recall correctly,” Kido says, tone clipped and hands folded in his lap, “I personally rejected your application on the grounds of inadequacy. Two weeks later I received a report from Jin about a civilian breaking into Forbidden Territory”

“You could have stopped me then,” Osamu says, watching his soulmate’s face grow grim.

“My sources told me you were doing it to protect someone.” Kido admits grudgingly, as though Osamu had a gun to this head.

“How does that justify-” Osamu says, before he reflexively leans back, as though he’d almost stepped on a landmine. He wasn’t willing to ask why his own goal resonated so deeply with Kido, or worse still -

If Kido had ultimately succeeded.

“Yes.” Kido says with a tone of finality.

“So why keep it secret? When I’m already in so deep?”

“And what would come from me coming clean?” Kido says, “would you have handed your friend’s black trigger over then? Would you have stayed out of the press interview? Because you understood?”

“Just because I understand,” Osamu replies, “doesn’t mean I have to agree.”

“Then there would be no use in revealing myself to you either way,” Kido concludes. Check and mate.

Osamu pauses, knowing how infantile his next question would sound, but presses on.

“Isn’t it lonely?”

Kido baulks, left hand moving to press against his scar.

“I’m not going to lean on a child,” Kido says, more to himself than to Osamu.

“No, no you’re not,” Osamu says quickly. Stubborn, he thinks, but he gets it.

“Is that all?” Kido asks, his face betraying a sliver of fatigue.

“I came because there’s something I want,” Osamu blurts, riding on the momentum of childish questions for the night. “There’s something I want, but it was meant for something else,” Osamu continues, hoping he was coherent in his deliberate vagueness, “But I still want it, and I was wondering-“

“There’s someone you want” Kido deadpans, “and they have a soulmate, shaking you up so much that you’re coming to me for advice.”

_Check_.

“You understand,” Osamu says, hoping to defend what was left of his ego “because you’ve been in a similar situation, haven’t you?”

“Trying to embarrass me, Mikumo?” Kido scoffs, “I’ve been young before, years ago,”

The car settles into silence.

“Go after them,” Kido says, or rather, mumbles halfheartedly. “You can shake off failures with age, but regrets, not so much.”

Osamu looks at his hands.

“…Kuga,” he hears Kido whisper.

“How did you know?” Osamu asks, a note of panic rising in his voice.

“What?” Kido asks, lost for a moment.

A beat passes, then it falls into place.

“His father,” Osamu sputters in horror, the same time Kido chokes out “His son,”

The conversation ends in a stalemate, only because Osamu flings the car door open and bolts.

“Jin-san helped out some,” Osamu summarizes, and Yuma nods.

“It was…an enlightening talk,” Osamu says, taking a calming sip of tea, “I figured out some things about myself,”

“Sounds interesting,” Yuma says, sufficiently curious, but not pressing.

“…I have someone I like,” Osamu says, and Yuma certainly takes the bait then.

“Who?”

“Care to guess?”

“Chika’s brother,” Yuma says with certainty.

“…Chika really can’t be trusted not to gossip.” Osamu sighs, “But no, that was years ago, I was just a kid.”

“We’re only fifteen,” Yuma laughs,

Osamu laughs with him, staring at the stars up above. He hasn’t felt fifteen since the day he stepped into Border, he doesn’t say.

“…Are they _like_ Chika’s brother?” Yuma prods

“No,” Osamu says, “Not at all,”

“Hm,” Yuma thinks, brows furrowed in concentration.

“Is this person…good at fighting?”

“Very,” Osamu says, “A rank level, even”

“Is this person good looking?” Yuma asks, almost teasingly. Osamu feels his hands get clammy even around the warm cup.

“…He has his charms,” Osamu admits, “I like his eyes,”

“Hmmm?” Yuma smiles, and Osamu is certain he knows.

“Is he smart?” Yuma asks,

“In his own way,” Osamu smiles, and because he can, adds on, “not in studies though, but two out of three isn’t bad”

“No, not at all,” Yuma agrees. “Who could it be indeed?” he says, like a cat letting a mouse run circles in its paws.

“Good at fighting,” Yuma lists, counting on his fingers, “Dashingly handsome, with stunning eyes-“

“I never said that,” Osamu laughs now. His heart is so light.

“I think I’ve got an idea of who it is,” Yuma says, his smile sly.

“Oh?” Osamu replies. God, his heart was beating so fast.

Yuma leans closer.

“Tachikawa-san?”

He can’t help it, he bursts out laughing at that, and Yuma’s laughing beside him, steadying the mug in his hand with his own. He’s never felt fifteen like this before, fizzed up like a shaken coke can.

“Osamu,” he hears, and Yuma’s suddenly too close, his cold, smaller hand in his own.

They kiss under the stars, his cheeks sore from laughing, and he feels like he’s flying.

x

 _Thank you,_ it writes on his arm.

“Dumb kids,” Kido sighs, but he understands.


End file.
